Train-control system



imam@ m9 1925er#o "i, E. CLARK ET 'AL TRAIN CONTROL SYSTEM ATTORNEY' 1,702,764 T. E. vCLARK ET AL TRAIN CONTROL sirsTEM Filed May 20', 1925 2 Sheets-Sheet INVENTOR. mu* z5. jai/l ATORNEY.

i Patented Feb. i9, 1929.

l UNITED STATES PATENT OFFICE.

THOMAS E. CLARK AND JAMES CLARK, OF DETROIT, MICHIGAN, ASSIGNORS TO CON- TIN UOUS TRAIN CONTROL CORPORATION, DETROIT, MICHIGAN, A CORIPORATION OF MICHIGAN.

TRAIN-CONTROL SYSTEM.

Application filed May 20, 1925. SerialI N o. 31,633.

This invention relates tomeans for controllin the operation of railway trains by means of igh-frequency currents of dilferent "wave lengths l propagated `in each of the several vblocksof the track by means of transmitting mechanism connected to the exit end of the block, the transmitting mechanism of each vblock being. controlled as to-wave lengths by `the, transmitting mechanism o-f the block in adv'aiica'and thetransmission mechanism of each block being inoperative unless the block of track to whichit is connected is occupied; and the 'object of tl'iis invention is to vprovide a transmitting mechanism of thScharaCter, and control devices therefor, which will propagate lcurrentof one predetermined wave length in the railsof its block vwhen the two blocks in advance'` are unoccupied, and will l propagate currentgof lanother wave length when either of the two blocks in advance is occupied, and also when the transmitting mechanism of the block 4in advance is'out of order.

A further object of this invention is to provide'instrumentalities on the locomotives and other vehicles equipped with air brakes, embodying collector coils adapted to pick up induced' current from adjacent lthe rails, thermal-junctions for translating the highfrequency induced current into direct cur-4 rent capable of ailecting a polar relay, and two: visible signal lamps to indicate the character of the current in the track.

, These'objects are attained by means of the present` invention which consists of a vacuum Y tube, proper circuits connecting. itto a current source and to the track rails, relays to select proper circuits so that the current created by the vacuum tube will be of one or another predetermined wave length, and

means 4'responsive tothe presenceof a vehicle' in the first or second track block in advanceA and in the block to which the vacuum tube isconnected for controlling 4tlieoperation of the relays.- It further consists of instrumentalities including collector coils on a locomotive or other vehicle, adapted'to pick up high-frequency .current from adjacent the track rails andtuned to the wave lengths of the severalA currents propagated therein, a pair of signals, a polar relay for closing circuits to these signals vaccording as one or the other collector coil picks up current, and circuits between this relay andthe instrumentalities -for picking up the current.

It also consists in a stick relay connected into thecircuits on the' vehicle and controlling the operation of a valve-in the air line of the vehicle,this relay being deeiiergized when the current picked up by the collector coils is-of one wavelength.- i

It also consists of the details ofconstrucu tion illustrated lin the accompanying drawiillgs' and particularly pointed out in the c aims.

In the drawings, Fig, i is `a diagram illustrating three track signal installations Combined with -control installations in different `positions,` together with a vehicle equipment adapted to c-operate therewith.

F ig. 2 is a diagram of a current transformer andl transmitter adapted for` use with the track installations shown in Fig. 1. Fig, 3

is a diagram of the locomotive equipment.

Similar reference characters refer to likeA t are indicated by lighter linesthan those which control units. The electro-pneumatic valve' belong to the train control installations, and v the blocks of track and the signal and control stations therefor Aare again indicated by the letters A to D` inclusive. The green, yellow and'red lamps of the signal stations again indicate clear, caution and danger,` that'is, lthat at least two blocks in advance are-unoccupied or that the second block in advance'is occupied, or that the next block in advance is occupied, respectively. Each signal installation and each train control installation is governed bythe station next in ad- Vance, and none of these installations function unlessthe tracks of the block to which it is attached is occupied.

Referring now to Fifr. l, the rails l and 2 are those where the traflic is always in one direction, that is, from right to left. The

imi

' blocks B and are, supposed to be occupied and two blocks in advance of block B unoccupied. A green signal light should therefore show at station B, a red light at station C and a yellow light at station D. The rails are divided into blocks by the insulating joints 3, and a single indicator 4 comprising three lainps is positioned at the entrance end of each block. A track relay 7 is connected to each block at its exit end by lmeans of wires 5 and 6 and is energized by the track battery 8 which connects to the entrance end of the blockby means of wires 9 and 10, a resistance 11 preventing damage to the batteryL when the rails are short-circuited by means of a vehicle on the track. i

The circuits to the lamps are controlled by the polar neutral relay 14 which is connected to the station ahead by the wires 15 and 16.

When positive current passes over the wire f wire 46, coil 47, and wires 48 and 49, and

15, the relay becomes energized and 'its armatures 14 and 14t swing clockwise; They swing counter-clockwise when negative current passes to the relay over wire 15, and remain in` their last position when no current passes over this wire which occurs when the block in advance is occupied, that is, when the track relay 7 of the station in advance is deenergized. In the present case, positive current is received by relay 14B,l but just before the train left block'C, relay 14C was receiving positive current over wi're 15, so thatits armatures e and f are in clockwise posi- In station B, current from the battery 13 flows to the lampV stand 4 over wire 17 and from the green lamp G back tothe battery over wire 18,' armature 14e, wire 19, armature 14d,` wire 20, armature 7, and wire 21, the armature 7 a being in dropped position which always occurs when the block to which itis connected is occupied. If no current were flowing` to the relay 14.over the wire 15, current would flow to the lamp stand from the battery and from red lamp R over wire 23, armature 14d, wire 20, armature 7l and wire 21 to the battery. When negative current flows to relay 14 over vwire 15, current Hows from the batteryover wire- 17 to the yellow lamp Y, then over wire 24, armature 14", wire 19, armature14d, wire 20, armaturel 7, and wire 21 to the battery. 1t will bel noticedthat these circuits are never closed when relay 7 is energized, and that wire 15 connects to the battery, from Vwhich it receives current, through the armature 7b which drops whenever the block is occupied.

A high-frequency current of one of two' wave llengths is propagated in the rails of each occupied track section or block, one wave length whenever the next or second block in advance is occupied, and the other whenever at least two blocks in advance are unoccupied. 1n station B, positive current is'coming in to relay 14 over wire 15. Current therefore flows from battery.,v 13 over wires 26 and 27 to the transformer 28 and thence over wires 29 and 20, armature 7 1 and wire 21 back to the battery.

This transformer connects to the rail 1 by means of the wire 30relay 31, and wires 32 and 5, and to the rail 2 by means of the-wire 33, condenser 34, and wires 35 and 6. It is shown diagrammatically in detail in Fig. 2. The wires 27 land 29 terminate in a motorgenerator 364 and in the filamenti37 of a vacuum tube 38, an adjustable resist-ance 39 in the filament circuit beingl provided to control temperature. The wire 27 also carries highvoltage currentfromthe motor-generator to the grid coil 40 to which it connects by means of wire 41 and the other end'of this coil connects to the grid 42,by way ofthe condenser 43and grid leak 44.

The circuitto the plate 45 consists of the this coil is shunted bythe variable condenser A5() whereby thescillations maybe limited to a predetermined wave length, and these oscillations are transmitted to the wires 30 suiiicient to cause it to attract its armature a, the result of which will` be explained later on. y A change in the wave length may be producediby shunting an additional condenser 53 across the plate coil -47, the circuit c onsisty ing ofthe wire 54 connecting to the wire 48,4

the armature a of. relay 55, wire 56, condenser 53 and wire 57 connecting to the wire 46.7 I

' This additional circuit is closed and the condenser is operative when the green signal lamp at the exit end of the block receives current, at which time current Hows from the battery and wire. 17 over armature 14, wireA 60, armature 14f, wire 61, relay 55 and wire 62` to return wire 20. This circuit is opened `at 14a when the first block in advance is occupied and at 14f, when the secon-d block in advance is occupied, so that the relay. 55 is energized only when the green signal lamp indicates clear vtrack for at least two blocks in advance. l. v'

A fifth relay 70 is so constructed that it gains and loses its energy very slowly. lits function is to close the circuit to the relay 14 ofthe next station in the rear whenever the',

rails of the block to which its own station is connected, are unoccupied, and the delayed loss of energy permits either of the circuits which conduct current to this relay 70 to be substituted for the other.

This relay receives current when the block to which it isA connected is unoccupied. One end of its winding always connects directly to the battery by means of wire 26. The

gized. Current now flows from relay 70 over,

wire 71, 'armature 70a, wire 73, varmature 7 and wire 21l to the battery as indicated in station C. The parts remain in this condition until a train enters the block, as indicated in Y station D, when the circuit to the relay 70 is again closed by the armature 31a. q

The wire 16B is' always connected'to either one or -theother end of battery 13Brthrough armature'c of'relay 14B. Wire 15B connects to armature b of relay 70B and therefore receives current when this relay is. energized and block B is unoccupied. `When block B is occupied, relay 7B is-de-energized and the I circuit overits armature a is open.4 If now the circuit over armature a of relay 311? is also open by failure of current from the` transformer `of s tion B, no circuit torelay A 70B will be closed until-the transformer is again operative. Failure of the transformer at any station therefore caussadanger indicationY at the next station in therear. If any block is occupied, the train control instrumentalities of the next two blocks in the rear will beready to propagate danger currents in therails of the blocks to which they are connected as soon as a vehicle enters the sections which are charged thereby.

A locomotive equipment is shown in Fig.'

3 and comprises the two collector coils or loops 100 and 101 connected to the thermaljunctions or thermo-couples 102 and 103 respectively and having the adjustable condensers 104 and 105 in their circuits so that each of these circuits may be tuned for proper wave length to receive one of the induced currents which travel along infront of the lead'- ing axle of the locomotive as it runs along a track section in `which high-frequency current is propagated as before described. The

`thermal-junctions convert or translate the picked uposcillating currents into direct currents and `the .two direct currents travel in' opposite directions over the wires` 106 and 107 to the polar relay 108 whose armature a swings clockwise when current'is received by.

a collectorcoil from ablock at whose exit end a green light is visible and :ounterclockvvise when a red or yellow light is visible under these conditions. That is, the relay armature swings to the position shown in Fig. 1 under danger conditions and to the position shown in Fig. 3y under clear conditions. These collector coils are preferably mounted on the pi t; .frame of the locomotive just ahead of the lead wheels and spaced a short distance from the rails'. v

Assuming that the clear current has been picked up by coil v and that it caused the armature ofv relay to swing to the Aposition shown in Fig. 3, current from the battery 110 flows over wires 112 and 113, armaturea of brake control relay 114, resistance -Y L15, 75

brake control relay 114, resistance 116 and wire 117 to the battery. Thi'shcircuit is nor-` mally closed.A Current also passes from` wire 112 over armature b ofsignal relay 118, wire 119, green lamp 120 and wires .121, 122 and 117 to the battery. Current also passes from wire 112 over armature 118, wire 124, relay 118, 'resistance 125, resistance 116'and1 wire 117 to the battery. We therefore have relays '114 land .118 energized over stickicircuits which remain closed until a current-is picked up bycoil 101. 'The resistances 115, 116 and 125 may be'equal-, and may be equal the resistance of relay 114. When the parts-.are as shown in Fig. 3 and current is picked'upby coil 101 to cause the armature 108.3. to swing -to the position shown inFig. 1, the current fromthe battery Awill take' anew path of`=less resistance over wires 1112 and 127, armatur=108, wire 128 and resistance 125, resistance 116 and wire 117,

short circuiting the relays 114-and 118,

which, when de-ener ized, drop their arma# tures. Current now ows'from wire 112 over armature 118'b and Wire'128 to .the red lamp 129 and over Wiresv121 and 122 to the battery. The red light will now signal danger conditions, that is, indicate totheengineer that theblock in advance is occupied. The same signal is given whenever the track way installation at the exit end ofthenext block in advance fails to operate.

Two forestalling keys 131 and 132 are located at different points, preferably at the -engineers and at the iremans stations, and

when both are depressed, currentwillflow from Wire 112 by way of wire-134, key 132, wire 135, key 131, wire 136 to relay 114 and resistance 116 and wire 117 to the battery.

-As the resistance of relay 114 is the 4same as that of resistance 125, sufficient current passes over this last [described circuit to energize relay 114. The keys must be kept depressed until thedocomotive has left'that portionof the track which `carries the current which caused armature 108.a to swing to the' right, whereupon this armaturewill swing to the dotted line Current still flows to :red lamp 129 and does ition shown in Figpj3.'

so until lamp relay 118 is again energized,

but current flows from'the battery over wires 112 and 113, armature 114, resistance 115, re`

lay 114, resistance 116 and wire 117 tothe battery, keeping 'r'elay 114 energized and permitting the forestalling keys to be released.

As soon as the collector coil 10Q picks up-a proper current and armature' 108n skwings to the position shown in Fig. 3, current passes Y to relay 118 over wires 112 and 127, armature 108L and wire 124. ,As soon as the relay 118 lifts its armatures,the current follows pressure is reduced so that'the brakes will be applied.

The pipe 147 leads to the electro-pneumatic valve -144 from a main reservoir, and when the valve 145 drops, this air flows through Y thev valve body 144, pipe 148, check valve body 149, and pipes 150 and 151 to the cylinders 153 and 154 respectively. When air flows to the cylinder 153, the piston 155 is forced inward to press the valve 156 into its seat, thus preventing air from flowing from the engineers trai-n valve 157 to the train pipe 158.

vThe engineer may, however, permit air to flowfrom this pipe 158 to reduce the pressure therein, the check valve 159 permit-ting such operation. y As the air flows to the cylinder 154, the piston 161 forces the disk-valve 162 inward from its outer seat ,onto its inner seat. When in its outer position, equal air pressure exists within the pipe 163 and reservoir 164, and above and below the piston 165 which connects to a valve 166. When the valve 162 is in its inner position, the pipe 163 and the space below the piston 165 are cut off .from the space above the piston and from the reservoir 164, and the air above the piston is permited to escape through the passage 167 and vent 168. P as-y sage 167 is regulated byvalve 169.

When the pressure above the piston 165 is reduced, the pressure below the pistonr'aises it and permits train line air from the pipe 163 to escape through the vent 170, and this reduction in train pipe pressure causes the brakes to` be applied. As the air above the pistonwould escapetoo rapidly unless the-passage 167 were made very small, the auxiliary reservoir 164 is provided so that the air therein will cause the pressure above the piston 165. to reduce very slowly.

As stated before,'the red lamp 129 receives current as soon as the locomotive reaches that portion of the track in which danger current is propagated, and the vengineer and fireman have ample time to depress the forestalling keys before the air from pipe 147 accumulates back of piston 155-161 sufficiently to cause the brakes to be applied. But should either engineer or reman be incapacitated Oain bringtion adapted to be mounted on a vehicle equipped with air brakes to co-operate with instrumeiitalities placed at intervals along the track and adapted to propagate high-frequency curren'tsof different wave lengths inl Vthe rails, which wave lengths depend upon the occupancy ofthe track, said vehicle installation comprising a pluarlity of current collecting devices adjacent to but spaced from the rails of the track and an electric circuit connecting to said'devices, means for changing the high-frequency currents into direct currents moving in opposite directions in said circuit, a polar relay in. said circuit adapted to be energized by said direct currents and having an armature; a'currentsource, an elecp tro-pneumatic valve controlling the operation of the air brakes of said vehicle, and a circuit between saidcurrent source and said electropneumatic valve controlled by the armature of said polarrelay.

2. In a train control apparatus, an installation adapted to be" mounted on a vehicle equipped with air brakes to co-operate with instrumentalities placed at intervals along the track and adapted `to propagate frequency currents of different wave lengths' inthe rails, which wave lengths depend upon the occupancy of the track, said vehicle installation comprising a plurality of current. coll lecting devices adjacent to but spaced from the rails of the track and an electric circuit connecting to said devices, means 'for changing the high-frequency ,currents into directV currents moving in opposite directions in said circuit, a polar relay in said circuit adapted to be'energized by said direct eurrents and having an armature;` a current source; an electro-pneumatic valve controlling the operation of the air brakes of said vehicle, and ua 'circuit between said current source and said electro-pneumatic valve controlled by the-armature of said polar relay, a second relay to open and close said last named circuit, manually operable means on the vehicle and an independent circuit between said second relay and"1 the current source.

3. ln a train control apparatus, an installation'adapted to be mounted on a vehicle equipped with air brakes lto co-operate with instrumentalities placed at'intervals along the track and adapted to propagate high-frequency currents of dierent wave lengths in the rails, whichy wave lengths-depend upon the occupancy or the track, said vehicle installation comprising a 'plurality ofl current collecting devicesadjacent tob'ut spaced fromthe rails of the track and' an velectric circuit connecting to'said devices, means forc'hanging the' high-frequency currents yinto, direct currents moving in opposite directions in said circuit, polar relay in said circuit adapted tobe energized said direct currents'and having anarmature; a currentsource, an electro-pneumaticyalve cont-rolling the operai tionfof the air brakes of said vehicle,and .a

`circuit between'sa'id current` source and said ".trollingltlie circuitA between said current, source and said electro-pneumaticvalve, ay

electr-@pneumatic valve controlled by the armature of said polar relay, a relay concircuit between said current source .and said relay adapted to be shunted by the cir'-V described in claim 1, -thermal couplesl for changing the high-frequency oscillating cur-' rent into direct current.

-5. Ina' railway vehicle installation .of a train control system, a current source, an electro-pneumatic valvea control relay, a

circuit between the current source and-valv.e,fi embodying an armature of saidrelay, a cirv cuit between said cur'rentsource-.and said armature *embodyingl A,another armature' of said relay, means to pick up high-frequency current from adjacent the trackson which the vehicle is moving, a relay influenced by said'l current, and a 'circuit embodying the arma-A ture of said last named relay 'to shunt the' v current from saidsource around \the control relay" to cause it to becomede-energized and the circuits embodying itsvarmatures to be opened. i .l

o. In a-- rail.w ay vehicle installation of a train control system, a currentfsource, an electro-pneumatic valve, a control relay, a

circuit between the current source vand valve,l embodying an 'armature of sall relay, a cir-- cuit between said current-'source and said armature embodying anotherarmature o-.said

relay, means to' pick up 'high-frequency'current from adjacent the tracks on which the vehicle is moving, a relay influencedby .said

current, and a circuit embodying the. armature 'of said last named relay to shunt the current from-fsaid-'source around the control relay tocauseit to become de-energized and the circuitsembodying its armatures tob e4 opened, and manually operablevmeans. toI

cause the control relay to be re-eergized Vto -close the circuitsl which` embody its armatures.`..""

7. Ina railwayvehicle installation of a train control system, the combination of aV normally closed electro-pneumatic 1 valve, and a brake systemadapted to voperate when-said'yalve .is open, a control relay for said valve, acurrent'source, a circuit be- .twe'en the current sourcel and vtheyalve embodymg` ari .armature of said 'control relay.

which circuit is held normallyclosed by said relay, a 'pair' of collector coils'adapteditd pickup ,control currents from the track rails,

l`'means operated by the picked up currents embodying al polar relayandl its armature, a pair of signal lamps anda relay to4 control the current thereto, circuitsl between the-cul`- "rent, source and said lamps embodying the armatures of'saidlast named relay, and 'eircuits -between said. current source 'and the' llamp control relayandth'e valve control re.'

l( and embodying thearmature of the po la'r' relay wherebyl the.' current Afrom said relays.

vsi ,source may be shunted laround said control z v' l8. In a train control apparatus,- an'install lation adapted, tobe mounted on a' vehicle- 4equipped with air 'brakes to .cooperate vwith -instrumentaliti'es placed) at ,intervals along the track and ad'aptedto propagate high-frequency currents of different wave lengths in the-rails, which 'wavelengths depend, upon the occupancy of the trac-k, said vehicle instal-l ation 'comprising current collecting meansV adjacent to but spaced from-the rails' of the traclqand an electric circuit connecting to said means,means for changingtnehigh-frequency o vresponsivemean'sin'said circuit adapted to currents into direct currents inl said circuit,

be'energized by said direct-currents 'and having movablem'echanism; a current source, an

electrofpneumatic-valve'controlling the operation of the air'brakesiof said vehicle, and-a circuit between saidcurrent source and said electro-pneumatic valve controlled' by said 

